QNAP TS-2483XU-RP review: 24-disk head unit NAS

QNAP has got very interesting monstrous NAS-s for working with large amounts of data. The model under review with the long name TS-2483XU-RP is a data storage system with a head unit for 24 3.5-inch hard drives. This gives the customer the opportunity to pack 384 TB of data into one system, using 16-terabyte hard drives , and to do without expansion shelves at all, which may be quite enough for the needs of a small enterprise.

And despite the fact that the scalability here is significant: up to eight 16-disk shelves, and even strange RAID modules with USB 3.0 interface, I can say that the QNAP TS-2483XU-RP is interesting in every respect , an ambiguous NAS model, which has something to praise and criticize.

Hardware platform

At the heart of the storage system is a 6-core (12-thread) Intel Xeon E-2136 with a nominal frequency of 3.3 GHz, increasing under load up to 4.5 GHz. By default, the NAS comes with 16GB of DDR4 ECC RAM (two 8GB modules), expandable up to 64GB.

Ask me, and I would prefer to see an AMD processor in such a machine, because security problems in the architecture of Intel processors surface on average once a quarter, and patches that close them lead to a significant drop in performance. And QNAP, unlike other NAS manufacturers, still has several lines where AMD processors are used, in particular, Ryzen in models with the TS-x77 index. Yes, who would have thought that the time would come, and we would consider the Intel server processor a disadvantage & hellip; But even among Intel's processors, there are much more worthy candidates for a place in the NAS. For example, the recently updated series Xeon D-1600 or Xeon D-2143IT processors have more built-in PCI-LAN controllers and 10-gigabytes built-in NAS controllers.

As for the QNAP TS-2483XU-RP layout, it is purely server-side: the high 4-unit case did not limit the developers' imagination, because they could realize any of their wishes in the form of a full length and height expansion board. One such desire was support for RDMA (iSER), a direct memory access technology for transferring Ethernet frames. For iSER to work, its support is needed both on the storage system and on the connected client or switch, and the Mellanox network cards have the best implementation of this feature. The QNAP TS-2483XU-RP comes with the Mellanox ConnectX-4 Lx NIC, a powerful NIC with an ASIC that qualifies the card as a smart card. SmartNIC network controllers (about what it is read our article), which are capable of performing some functions to analyze network traffic without loading the CPU.

Returning to iSER, we can talk about such an advantage of this technology as an increase in random access speed by 40-60% and a decrease in access time. Also, with intensive network traffic, the server CPU load is reduced. The installed controller has 2 10Gbe Ethernet SFP + slots, 25 and 40 Gigabit interfaces are optionally available.

On the motherboard itself, four 1-Gigabit network ports are available to you, as well as six USB 3.1 (two Type-C and four Type-A). The configuration of network ports is optimal for using the device as a network gateway: optical Uplink for WAN and 4 copper interfaces for LAN.

When it comes to USB 3.1, QNAP has a very interesting take on this interface: the company offers rack-mountable expansion shelves that have their own RAID controller. Probably, constant direct access to data on these disk shelves is not meant, but they are planned to be used for backup or for archived data. In such disk shelves, configuring a RAID array can be carried out both through a common Web interface and by jumpers on the case, while you can easily disconnect such a shelf from the storage system and connect it to a laptop, for example, if you are standing near a server cabinet, and you suddenly ran out of disk space on your laptop :). But this is generally not accepted: a serious storage system is a single head unit plus expansion shelves, which in turn are nothing more than a SAS backplane in a steel case with a power supply. QNAP also has such expansion modules for 16 disks, which you can connect to this NAS up to 8 pieces in series, 4 for each port of the SAS-12G2E SAS adapter (purchased separately). QNAP currently has 3 expansion modules with RAID controllers and USB 3.1 (TR-series): one 4-drive rack-mountable and two desktop 2- and 4-drive units.

For SSD caching, a sign of good form is the installation of separate bays, usually on the back of the storage case, and QNAP has such solutions in the corporate segment, but the TS-2483XU-RP is still a budget solution, and separate bays for solid state drives not here, so either donate one of 3.5 for SSD bays (fortunately there are already 24 of them), or install a special PCI-E card for mSATA/M.2 drives. And I must say that in the production of such boards, QNAP has succeeded like no other. They learned how to produce combo boards with a 10 Gigabit controller and 2 mSATA/M.2 slots. We have already met such a controller in I do not admire such a review of the desktop ... Keep in mind that there are different adapters for mSATA and M2 drives: boards with index QM2-2 S - for mSATA and QM2-2 P - for PCI Express M.2. Well, if you don't need a 10-gigabit twisted-pair network, then there is a version of such a card without a network, including a 4-disk one. Please note - this controller has active cooling for drives, and the fan status is monitored through the storage operating system, so there is no point in using non-original components here. In general, if we put aside fears about the unreliability of SSD drives, and do not think about the lack of hot swapping, then such adapter cards are the best solution for a NAS that has 4 PCI Express slots empty.

For testing, we used Toshiba N300 hard drives, designed specifically for NAS. In our testing, we used both 14 TB helium HDDs and regular, ''air'' ones. volume of 6 TB. With a good SSD cache, there is usually only one requirement for hard drives: work without breakdowns. According to Backblaze statistics , Toshiba hard drives have a failure rate of less than 1.5%, and although this is not a record, they still deserve to work in a data center.

For caching read/write operations, you must use a fault-tolerant RAID array of solid-state drives, at least a RAID 1 level, that is, a mirror of two disks. Even if you installed 2-3 QM2 adapters, you can combine SSD drives on these controllers into one common array. By the way, I never tire of repeating that in addition to traditional, simple and straightforward SSD caching, QNAP also has a QTier function for automatically dividing storage space into layers: slow for hard drives and fast for SAS HDD/PCI-e SSD. We examined this technology in detail not only on the example of the corporate TVS-951 for digital studios . For those who are too lazy to read, recall that QTier, unlike SSD cache, sums up the volume of a solid-state RAID array to a disk one, and transfers the most requested data blocks to the SSD according to a schedule. Moreover, this may not necessarily be the entire file, but also some parts of iSCSI LUNs.

A tale of a failed GPU experiment

Last year, QNAP reasonably decided that the future lies with storage systems in which GPUs can be installed for tasks related to AI and ML computing, and even released several desktop devices optimized for such tasks. In our review of the QNAP TDSa-16489 video machine we tested running on an embedded hypervisor, for example for CAD applications. Then I complained that that old NAS did not have additional power for any powerful video cards, and the developers heard our comments.

From a power point of view, everything is perfect: the 800W Delta fault-tolerant power supply ensures that there is enough power here even if the NAS is completely filled with hard drives and a pair of gaming graphics cards are installed.

The storage case allows you to install two 2-slot video cards in order to later use them for video transcoding, accelerating artificial intelligence or forwarding to a virtual machine, where you can do whatever you want with them. If you just need to run Python code under Tensorflow, you can use the Jupiter server, which runs in a container through the Container Station. Of course, it only works with Nvidia graphics cards, but that's not a problem.

There is, however, one "but": the video card must be on the compatibility list indicated on the QNAP website, and this list is not long: there are no professional Tesla accelerators or proletarian P106-xxx, so cards created for GPU -calculations go past the checkout. Personally, I do not understand what kind of GPU computing we can talk about and why then add Tensorflow support to the NAS if the Nvidia license agreement does not allow the use of gaming video cards for professional calculations and 24x7 operation. My experiment failed: With P106-090 QNAP installed TS-2483XU-RP did not start. At the same time, when installing a compatible gaming or office video card, you can use the GPU to launch a virtual desktop, forward the GPU to the Windows environment of the virtual machine for the operation of a codec, and so on: all this is described in our review.

QNAP also has its own Mustang series computing accelerators, but they are based on exotic chips: Arria 10 1150GX (Mustang F100), Intel Movidius Myriad X VPU (Mustang V-100) and a rather eccentric Mustang-200, which is two computers with Core i5/i7/Celeron processors, memory and SSD on one PCI Express board. They are planned to be used for working with ready-made models of artificial intelligence, for example, for face recognition in video surveillance systems.

For this purpose, QNAP announced the OpenVINO platform, which supports its own accelerators, into which you can load a model from Tensorflow or Caffe. I hope that soon we will be able to test this solution, but as you understand, you will have to create the model yourself. However, given that today everyone is literally obsessed with computer vision, here QNAP has a very good foundation for the future.

Today, major server vendors are slowly ditching hot-plug fans, and QNAP has supported this trend. Well, the cooling systems in such machines almost always operate at minimum speeds, due to which they quietly work out without replacement for 10 years, and often even more. The use of 92mm fans allows the QNAP TS-2483XU-RP to operate with a noise level of only 28.7dB, which means it can be kept in an open cabinet in the same room as staff.

Software

QNAP uses a single operating system for both home and corporate NAS, but the packages supported may vary. Of course, QNAP and FreeBSD-based have a QES operating system for the two-controller ES series, where ZFS with deduplication and high data integrity is supported, but these two operating systems are not compatible with each other, and packages are not exchanged. In general, with traditional and container virtualization, there seems to be no need for dozens of programs installed from the QNAP repository. Well, except for those that are closely related to data backup and storage.

One of the most demanded functions today is snapshots, snapshots. Yes, of course all storage manufacturers have them, but QNAP managed to implement it on the EXT4 file system, which, along with NTFS, has earned a reputation as the most reliable and fastest. You can replicate snapshots to external data storage, thus replacing backups. Snapshots work for both regular file folders and iSCSI LUNs, and in the snapshot manager you can:

• configure snapshots on a schedule,
• reserve space for snapshots,
• import snapshots from another NAS
• restore a single file or LUN to a previous state,
• clone snapshot to new LUN or volume.

Lacking, perhaps, is the ability to mount a snapshot in iSCSI target to work with multiple versions of data at the same time, but this is a rare opportunity, and very few people have it.

Testing

Let's start with traditional synthetics when connecting via iSCSI for a disk formatted in NTFS with a cluster size of 4 KB.

Go to sequential access.

SSDs used in the test are frankly weak in streaming write tests, so we see an advantage over HDD only in reading, where the speed matches the bandwidth of the network port.

In addition to the traditional IOPS values ​​that we used in previous NAS reviews over the past two years, we pay attention to the response time, and here's why. Today, in almost all use cases of NAS-s, SSDs are used to speed up work with a disk system, and IOPS values ​​exceeding hundreds of thousands remain unclaimed: there are simply no such workloads. But the access time floats very much, and just as steeply depends on the type of load, its intensity and storage architecture. Some experts believe that this is the main benchmark for storage performance, and access time should not exceed 20 ms. Well, let's take a look at an array of two Transcend TS256GMTS800 256Gb SSDs installed via a QNAP QM2 adapter and combined into RAID 1.

QNAP TS-2483XU-RP even with simple SSD disks easily keeps synthetic load below 1 ms up to 16 threads, but for databases, of course, it is better to choose expensive Enterprise SSDs. Just in case, I want to remind you what our Oracle pattern looks like:

Complete patterns you can find in this review

And if we adhere to the opinion that the typical access time should be no more than 20 ms, then the storage system in question, roughly speaking, in the basic configuration is capable of working with 16 threads of the Oracle database.

Usage Recommendations

Size always matters, and 24 disks in the head unit is an opportunity to build storage systems without any expansion shelves at all, which means without extra costs. Such a huge volume is enough for any task, and this niche is the native habitat for the QNAP TS-2483XU-RP, here it has no equal, especially considering the software capabilities of QTS and 4 free PCI-E slots inside. If you put two boards for 4 NVME drives each in this NAS, then you will completely close the issue with a fast SSD layer, which you can use both as a cache and as a separate volume, and may you not have Hot Swap for these SSDs, but as they say, e sweat. Other usage scenarios run across a weak processor, or a small maximum memory size, and to make it easier for you, focus on the following list.

For what purposes QNAP TS-2483XU-RP is best suited:

• storage of video recordings of your NVR system
• creating and storing backups (the server can be started on the NAS itself)
• hosting virtual machine images
• network gateway with OpenVPN and DPI at 10 Gbps
• common file sharing node (block and file access for DBMS, SAP and other applications with high read/write intensity).
• GPU transcoding media server

For what purposes QNAP TS-2483XU-RP is not suitable:

• for serious virtualization
• for machine learning/artificial intelligence tasks
• as a Python compute node

Predictive troubleshooting has become one of the most interesting storage trends in recent years. This is when, for example, all NAS-s of a company send telemetry to the head office, and artificial intelligence, based on sensor readings, tries to predict in advance the failure of one or another component. This approach allows you to solve cases even before they appear. QNAP does not yet have such technology, but it is available in Seagate IronWolf hard drives, and is discussed in detail by us in. All QNAP NAS supports Seagate's advanced IronWolf HealthManagement disk health diagnostics, and some of the predictive value of your most valuable storage item can be obtained simply by choosing dedicated hard drives designed specifically for NAS.

Michael Degtjarev (aka LIKE OFF)
26/11.2020